/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 * Adapted for NetBSD/x86_64 by Frank van der Linden <fvdl@wasabisystems.com>
 */

#include "DEFS.h"

ENTRY(memset)
        RETGUARD_SETUP(memset, r10)
        movq    %rsi,%rax
        andq    $0xff,%rax
        movq    %rdx,%rcx
        movq    %rdi,%r11

        cld                             /* set fill direction forward */

        /*
         * if the string is too short, it's really not worth the overhead
         * of aligning to word boundaries, etc.  So we jump to a plain
         * unaligned set.
         */
        cmpq    $0x0f,%rcx
        jle     L1

        movb    %al,%ah                 /* copy char to all bytes in word */
        movl    %eax,%edx
        sall    $16,%eax
        orl     %edx,%eax

        movl    %eax,%edx
        salq    $32,%rax
        orq     %rdx,%rax

        movq    %rdi,%rdx               /* compute misalignment */
        negq    %rdx
        andq    $7,%rdx
        movq    %rcx,%r8
        subq    %rdx,%r8

        movq    %rdx,%rcx               /* set until word aligned */
        rep
        stosb

        movq    %r8,%rcx
        shrq    $3,%rcx                 /* set by words */
        rep
        stosq

        movq    %r8,%rcx                /* set remainder by bytes */
        andq    $7,%rcx
L1:     rep
        stosb
        movq    %r11,%rax

        RETGUARD_CHECK(memset, r10)
        ret
END_BUILTIN(memset)